Why Would I Choose 00-SF ?

[Semi Fast]

After deciding that I wanted to build my own turnouts to use with SMP/C&L plain track, I spent a considerable amount of time perusing RMWeb and other sources researching the topic.  Like many others, I concluded that “00-SF” ticked the right boxes and so I am now collecting the appropriate tools, gauges, etc. to make a start this winter.  Part of the preparation has been to follow the related discussions on RMWeb, hoping to pick up tips and information prior to starting.

Unfortunately, most 00-SF discussions tend to descend into a more general debate regarding its fitness (or otherwise) for purpose.  This makes it rather difficult to pick out the useful content to either add to one’s knowledge or inform an opinion on it’s suitability for an individual.  I suspect that some folks choose not to contribute to these threads for fear of being branded ‘pro’ or ‘anti’.

So, to help anybody in a similar position to where I was a couple of years ago I have attempted to summarise the salient points of 00-SF.  Please note that while I will attempt to be as objective as possible, I have already decided to use 00-SF myself.

 

• 00-SF is for 4mm/1 foot, UK outline, standard gauge modellers.  It has no relevance to H0 or any other scales and gauges.
• 00-SF is a label.  It is not an “official” standard.  Another way of describing it would be “EM-2” (i.e. EM gauge minus 2mm).
• By accident rather than design, 00-SF enables most modern 00 wheelsets to perform smoothly and reliably.  While some ‘tweaking’ of back-to-backs may be required, it’s probably no more than would be required to get good running with other track standards (i.e. manufacturing issues, interpretation of parameters).
• 00-SF is only applicable to hand-built turnouts (and diamonds).  There is no relevance to RTR.
• 00-SF is an option for those who have already decided to hand-build – there are more significant reasons for choosing hand-built over RTR other than 00-SF’s particular dimensions.
• Adopters of 00-SF generally apply the gauge-narrowing to 16.2mm only to switches and crossings; all other trackwork uses the standard 16.5mm.
• There are a number of people who have built and operated 00-SF and have then shared their experiences on RMWeb and elsewhere.  I have only been able to discover positive feedback from these individuals.  As far as I am aware, nobody has tried 00-SF and subsequently found it unsuitable for modern 00 RTR or typical kit wheels.
• To most people, the narrower flangeways delivered by 00-SF are a noticeable improvement over those resulting from the traditional standards.
• Some people claim that 00-SF is flawed and will lead to imperfect running of unmodified 00 wheelsets.
• Some people point out that 00-SF is not a standard recognised by any international or national body and so raises risks of non-interoperability for those wishing to share stock.

I would be interested to hear other people’s views on 00-SF – in particular, why they think I should or shouldn’t adopt it.

 

Andrew

Edited July 30, 2021 by martin_wynne
reference to 4-SF removed

[Joseph_Pestell]

That seems a very good summary. And I hope this thread is more "positive" than some have been.

 

The non inter-operability is probably the main downside but that may not matter at all in your context. After all, none of us who use OO in whatever form can share stock with EM/S4 modellers either and we live with that choice.

[trisonic]

It does work and it’s simple (whisper: the same principals work on H0 except you don’t have to modify sleepers/tie gaps if you use decent running track).

Nothing else I can add.

 

Best, Pete.

[Junctionmad]

I would disagree with point #3. The purpose of 00-SF was to bridge the gap between RTR and finer scale wheels. If you simply wanted better looking 00 track and the ability to handle finer wheels then DOGA-Fine is available and pre dates 00-SF to my knowledge

[Arthur]

I'd say that is a pretty good summary Andrew. All that I would add, pertinent to another thread, is that there is no commercial support nor organisation involved. C&L manufacture and sell suitable track gauges, that is it. Everything else is standard 4mm track building components.

 

Edit. Addressing Junctionmad's point, and just to be clear, nobody claims 00-SF to be the only solution to 'improving' the look and performance of 00 track work. Others are available, do your research and pick what suits you best. Respect the choices others make.

Edited September 1, 2015 by Arthur

[David_H]

Hi Andrew - you make some good points. I have also been looking at OO-SF for nearly a year now. I have a slightly different set of dot points to you. In the spirit of avoiding the usual taking points, I'm happy to accept that different people can get different things out of a particular subject. So while some of my talking point might mirror your own, others might not - but that doesn't make me right and you wrong, it's just a different look at the same subject.

 

And I hate this dancing around, so I'll just deal with the facts - at least as I see it.

 

• OO-SF is a track standard, not a wheel standard. It can be for anyone to use for any scale or wheels they can make it work, if they desire.
• Some, perhaps many, wheelsets can operate without modification. Anecdotally, many people have found that their wheelsets work fine, but others having heard this have tried for themselves and found the opposite. I am one of those people, for example. So such an experience can leave them confused and frustrated and perhaps questioning. The publishing of some numbers really helps modellers decide if their wheels would work or not work - but the success or failure of the wheels has nothing to do with OO-SF, which is a track standard.
• I think the strongest reason for adopting OO-SF is to be able to run code 88 or semi-scale wheels, which do not run well on traditional HO standards. That does not mean that OO-SF runs better than those other track standards, because those track standards were never designed to run those wheels in the first place.
• Gauge narrowing through turnouts must result in a greater minimum radius for the same wheels used, especially if the turnouts are curved. The same principal applies to gauge widening on normal track - widen the gauge, you can run smaller radii; narrow the gauge, greater radii. This may be of no importance to some, or critically important to others. But it is a fact. (edited in italics)

There are a few options for running wheels with a smaller width:

• have wider flangeways with controlled depths so that narrower wheels run on their flanges. The European NEM standards have this written into their track and wheel standards, for instance. It has been mentioned many times on many forums that a good way to get reliable running of smaller width wheels through traditional wider flangeways is to fill in the bottom of the frogs with small strips of thin metal or plastic to allow for flange running- and some manufacturers make frogs this way so you don't have to modify anything. This isn't new. (edited: additions in italics)
• use a finer track standard designed for those wheels such as Fine:HO or the UK equivalent DOGA-Fine. Again, not a new idea.
• use the current HO standard and just have narrower flangeways, which are still within the published standards. I don't know why this isn't discussed much, but I have since found some older threads on the subject, so I am looking into it further.
• narrow both the flangeway and the track gauge - OO-SF.

That's four options, each with their plusses and minuses. What you choose to use is up to you. Is OO-SF better than the other three? I guess it depends upon what is important to the individual concerned.

 

What do I think? My only gripe - my one and only negative - is the inability to find out factual information to help me decide for myself. Too many claims made that, when I go to the trouble of building a turnout and testing, turn out to be false. I feel I have wasted considerable time. And believe me, it is not helpful for some poster to airily claim that I "should" have known such and such, or that this-and-that does not apply, when such claims for OO-SF are made multiple times. "Try it for yourself, you can't go wrong" - well, I did, and it didn't work - for me. Trying to work out why and nail down some actual numbers uncovered the culprit - not every wheelset or wheel standard will work. That is not a drawback for OO-SF, which is a track standard - but it is not helpful to have some wild claims made to the contrary that turn out to be false. (edited: emotive language struck-through, my apologies)

 

I'm glad Martin helped out, he put up some numbers on a OO-SF web page. Now everyone can look and decide for themselves if their wheels will work.

 

My last point - OO-SF will work or not work depending upon engineering, not on your beliefs or motives. Beelzebub can use OO-SF if he wants to. Questioning someone's motives or other such clap trap belongs in a cult, not a hobby.

Edited September 1, 2015 by David_H

[Semi Fast]

Junctionmad:

 

I'd forgotten that DOGA-Fine gave the narrower flangeway, so cosmetically it gives the same result (strike point 8 from the list).  However, the significance of point 3 (should have numbered them!) to me is that the gauge-narrowing of 00-SF gives a smoother operation than DOGA-Fine - at least as I understand Martin and others explanations.  In terms of making a choice, I don't suppose the origins make much difference.

 

Arthur:

 

Indeed - despite what some seem to think, "pushing" 00-SF has no purpose being on anybody's agenda.

[Siberian Snooper]

A lot of us only use 16.2 mm through the crossing the rest is 16.5 with the transistion in the closure rails, thats the bit between the switch and wing rails on the full sized turnout and after the the "V" rails at the heel end of the turnout, the exception is where 2 turnouts form a crossover, where the two rails between the "V" remain at 16.2 mm. In one or more of the other threads Gordon S. has added a diagram.

[Semi Fast]

David_H:

 

Thank-you for your considered response.  Could you summarise which wheelset/wheel standards you had problems with (and how those problems manifested themselves)?  Now you have reminded me, I do remember this being in a thread on here but I can't find it just now.  Could you post a link?

 

I do rather like the last paragraph of your post above.  I've no objection to enthusiasm for a thing, but vilification annoys me intensely.

[David_H]

David_H:..  Could you summarise which wheelset/wheel standards you had problems with (and how those problems manifested themselves)?  ...  Could you post a link?

Hi Andrew - link is here.

 

In brief, using published wheel standards, it appears that the US NMRA HO standard wheels only have a small overlap (0.06 mm) that allows operation through the narrower OO-SF frog. Furthermore, the NMRA has a "target" dimension to encourage manufacturers and modellers to aim for, and this dimension is at the top end of their back-to-effective-flange (BEF) range and outside the (greater than) maximum BEF allowed for OO-SF operation. Wheels that are wider than the allowed BEF will pick the point of the frog and try to go the wrong way through.

 

Anecdotally, i.e., from the actual experience of actual modellers who were kind enough to reply to my posting, many US style wheels did work for people's OO-SF turnouts. If I may summarise for others (and please forgive me if I get it wrong), the consensus appeared to be that older US wheels were made to an older NMRA standard, now defunct, that does happen to allow for running through OO-SF. I went back and measured some of my locomotives (mostly recently bought) and found that five wheelsets out of the 22 measured would make the grade to run through OO-SF, the others were too wide. I had already measured (and reported on in an earlier post) a set of semi-fine code 88 wheels that I had bought from Reboxx. They are great looking wheels that come in a large number of axle widths so you can pick what works best, and meet the relevant NMRA wheel standard, but were all at the top end of the NMRA range and therefore kept picking the point of the frog when I test ran them through (this started my quest for more information).

 

Having wheels too wide (or too narrow) is not necessarily a problem. It's an embuggerance, sure, to have to measure up and reset any errant wheels, and difficult to do for older steam locomotives. So I can see how, if a (UK) modeller's personal collection of rolling stock is already the right size, and if they know that they can purchase more of the same, that OO-SF holds appeal because no modification (apart from swapping out older wider wheels for slimmer looking ones) needs to be done. The problem arose for me because that important caveat - it works for UK wheels - was not made obvious. In my defence, I could find no actual data on what the requirements are for wheels to successfully run through an OO-SF turnout.

 

In response to my plea for more information there is now written down data for the required maximum BEF. It becomes a simple case of working out what wheels work and what don't.

Edited September 1, 2015 by David_H

[davknigh]

Not wishing to stir up trouble but purely as a curious observer; if you are going to go to all the trouble/fun of building your own track, especially if RTR will not run on it without modification, why not go to EM or P4? Just wondering...

 

Cheers,

 

David

[David_H]

Not wishing to stir up trouble but purely as a curious observer; if you are going to go to all the trouble/fun of building your own track, especially if RTR will not run on it without modification, why not go to EM or P4? Just wondering...

 

Cheers,

 

David

I think that you may have perhaps misunderstood - from what I read in many postings "RTR" will run on OO-SF without modification. So if that does work for a modeller, and they have an existing OO layout, then they may decide that is easier than going to EM or P4. You'll have to ask them, of course, but I think I am pretty safe in saying that.

 

It's just that perhaps "RTR" means different things to different people, based upon their purchasing history. I think maybe the distinction may need to be drawn between a US-based wheel, and others. I'm not familiar with the UK market, and I can only report my own experience with US-based products. But I do not claim that this also applies elsewhere.

 

OO-SF modellers appear to be very happy with their choice. That would not be the case if they had trouble with RTR wheels, I think.

Edited September 1, 2015 by David_H

[Semi Fast]

DavidKnigh:

 

Good question! If I'd not had a 35 year break from the hobby, I probably would be into EM or P4. I have decided to accept the compromise and go to good looking 00 as my main interest is steam and I just can't try and learn too much too quickly.

[Arthur]

If I could wave a magic wand, yes, I'd go P4. However, with plans for quite a large layout I cannot be bothered with changing wheelsets on a large number of items of RTR loco's and rolling stock plus probably 50 or 60 kit built loco's, all currently 00, built over several years. And, in truth, I can barely see a difference between hand built 00 track work and EM. I often have to look twice at good 4mm track to determine the gauge. It just doesn't jump out at me. Others may find that heresy but it's what I find.

 

So, 00-SF works for me, other opinions are available.

Edited September 1, 2015 by Arthur

[dasatcopthorne]

Guys.

 

I still think some of you are looking at 00-sf in the wrong way. From the wrong angle.

 

Forget why it came about, and how it came about doesn't matter.

 

Whatever its original purpose, its purpose now is that most, and I really do mean most, UK RTR will run through 16.2mm P&C without modification and at the samer time, have a smoother ride.

 

I still set all my rollingstock wheels to a BtB of 14.5mm. That's easy done. Surely anyone contemplating building track will be capable of re-setting plain wheelset BtBs. Its the locos that cause the problem. Yes, diesels are mostly re-gaugeable but the steamers can be almost impossible.

 

I went down this road when I set out to build 00 track, as I have done for a few years, for a new Club layout. It used to be copper clad but I wanted something better. Proper chairs and sleepers. Then I discovered that some of the modern steamers had wheels glued into stub axles. Club members couldn't be asked to re-gauge their steamers, so 16.2mm it was. Why not, to be honest.

 

So, may  I stress that this is the angle you should view 00-sf from.

 

If you're happy with any other gauge, go for it. If you are happy to re-gauge all your BfBs, it really doesn't matter what you choose but stick to what  you choose.

 

ps I also build plain track and use the same gauges.

 

Dave

[Junctionmad]

With the greatest respect to HO modellers and NMEA adherents. It's worth reminding everyone that it's 00-SF not H0-SF. it's only relevant to 4mm modellers using 16.5mm gauge , typically UK modellers. Talking about code 88 wheels is just confusing people.

 

As to why not go EM. simple, many people want the flexible prototypical geometry of hand built track , without having to potentially re wheel their stock. I suspect this is the only reason people are adopting 00-SF.

 

In my case I'm modelling an irish layout in 00 , so EM would still be wrong !!!!

 

With 50 points excluding fiddle yard , going p4 would be an exercise in madness !

[Junctionmad]

There are a few options for running wheels with a smaller width:

have wider flangeways with controlled depths so that narrower wheels run on their flanges. The European NEM standards have this written into their track and wheel standards, for instance. It has been mentioned many times on many forums that a good way to get reliable running of smaller width wheels through traditional wider flangeways is to fill in the bottom of the frogs with small strips of thin metal or plastic to allow for flange running- and some manufacturers make frogs this way so you don't have to modify anything. This isn't new. (edited: additions in italics)

use a finer track standard designed for those wheels such as Fine:HO or the UK equivalent DOGA-Fine. Again, not a new idea.

use the current HO standard and just have narrower flangeways, which are still within the published standards. I don't know why this isn't discussed much, but I have since found some older threads on the subject, so I am looking into it further.

narrow both the flangeway and the track gauge - OO-SF.

 

There is no prototypical uk basis for filling the frog. It's seems incredibly " toy train" to most modellers

 

DOGA -fine is just H0 ( ie 16.5) with narrower flange ways and check rail gaps. The big issue is that it will typically not accept RTR wheels.

 

00-SF , will accommodate a range of British outline , RTR wheels and finer wheels. That's it point.

Edited September 2, 2015 by Junctionmad

[Junctionmad]

Junctionmad:

 

I'd forgotten that DOGA-Fine gave the narrower flangeway, so cosmetically it gives the same result (strike point 8 from the list). However, the significance of point 3 (should have numbered them!) to me is that the gauge-narrowing of 00-SF gives a smoother operation than DOGA-Fine - at least as I understand Martin and others explanations. In terms of making a choice, I don't suppose the origins make much difference.

 

Arthur:

 

Indeed - despite what some seem to think, "pushing" 00-SF has no purpose being on anybody's agenda.

You mis-understand. DOGA-Fine gives very smooth operation, BUT ..

 

Currently , you can build an 00 layout with PECO or similar RTR track , this is basically DOGA -intermediate , ie 1.3mm flange ways . This allows a wide variety of 00 RTR stock to run.

 

However if you use DOGA intermediate or similar( PECO) , you will experience some wheel drop on finer scale wheels , often found in kits etc. whether this bothers you or not is the question

 

Since the next available standard is DOGA -fine , which precludes most of today's RTR uk outline wheelsets in reality anyone contemplating DOGA -fine is far better going to EM or P4

 

Hence into this gap , steps 00-SF, while it wasn't conceived for this purpose, it NOW acts as a " bridge " standard, providing similar running for RTR to DOGA -intermediate and better running for finer wheels , it also improves the turnout cosmetically to boot.

 

In essence you get the running qualities of DOGA-fine with the wide acceptance of wheel types of DOGA-intermediate

 

In reality , I suspect only 00 modellers searching for better track geometry, but who wish to utilise 00, are going to consider 00-SF.

In the past I actually built PECO compatible turnouts , but now I build 00-SF ( because there no downside)

.

Edited September 2, 2015 by Junctionmad

[47137]

My own reason for choosing 00-SF was to make better-looking points and to keep interoperability with the 00 gauge club layout. RTR wheels set up for 00-SF also run through Peco points and 00-BF, though not necessarily the other way round. The thinnest wheels I possess measure code 91, and while wheel drop happens on the coarser standards, this was not a decision maker for me.

 

This interoperability lets me run my trains on a main line club layout from time to time as well as on my own layout, and lets me use some Peco points on my own layout too.

 

The fundamental dimensions are check gauge and the crossing flangeway gap. The track gauge is derived from these (add together). If I needed to run coarser wheels which won't fit a 1 mm flangeway, I'd look into a 1.1 mm flangeway with 16.3 mm gauge, or 1.2 mm with 16.4 mm gauge before committing to 00-BF. The only extra tool needed is different feeler gauges for the crossing flangeway.

 

My own track has a representation of British HO scale timbering, as preparation for a British HO layout. I discovered the HO-SF setting in Templot rather late in the day, so I think it would be best to say my SF efforts are 00-SF not HO-SF. The differences in geometry are too minor to get into detail here, and calling it 00/HO-SF would be wrong.

 

When I ponder a new layout, the interoperability factor always seems to come back to me and win. And so I'm tending towards the British HO option rather than EM at the moment.

 

- Richard.

[Semi Fast]

Thanks everybody for the constructive contributions  .

 

Junctionmad, I think you've better described what I was trying to say.  I get it in my head, but I'm not sufficiently experienced to clearly express it on the page; partly why I started this thread.

 

I find it quite interesting that however often 00 modellers emphasise that 00-SF is only really effective for British/4mm/00 requirements, it seems there are H0 guys looking at it as well.  What's the attraction?

[martin_wynne]

On 01/09/2015 at 13:57, Junctionmad said:

I would disagree with point #3. The purpose of 00-SF was to bridge the gap between RTR and finer scale wheels. If you simply wanted better looking 00 track and the ability to handle finer wheels then DOGA-Fine is available and pre dates 00-SF to my knowledge

 

Hi,

 

Not so. The original purpose of 00-SF (then called "EM minus 2") was to demonstrate the improved running of BRMSB 00 wheels on 1.0mm flangeways (as used in EM) instead of the usual 1.25mm flangeways used for BRMSB 00.

 

That was in the early 1970s. I don't recall anything equivalent to DOGA-Fine being in use at that time, otherwise there would have been no need for "EM minus 2". At that time there was no thought of any relevance to RTR models, which were children's toys in those days.

 

I have written more about the history of 00-SF here: http://www.rmweb.co.uk/community/index.php?/topic/94567-00-sf-and-00-bf-can-you-mix/page-10&do=findComment&comment=1992551

 

Full information about 00-SF is on its own page here: https://85a.uk/00-sf/

 

regards,

 

Martin.

Edited July 30, 2021 by martin_wynne
updated link

[MikeH_83]

I am planning on a oo-sf layout after seeing what Gordon S has done and has said about it,  My one concern? how often do you come across a modern rtr loco that isn't within oo-sf tolerances?  My aim is to go mostly steam and I think these b2b's would be slightly harder to adjust?  I only really plan on buying the newer stuff or hopefully one day kit making but I don't want to be spending alot of money on loco's to find alot of them out of gauge if it's going to be a pain.  Diesels, coaches, wagons.. not a problem! 

[martin_wynne]

00-SF modellers appear to be very happy with their choice. That would not be the case if they had trouble with RTR wheels, I think.

 

Hi David,

 

I think one point you may be missing in not being familiar with 00 modelling in the UK, is where many such modellers are coming from.

 

The vast majority of 00 modellers use commercial track, namely Peco Streamline 00/H0 track. For which the check gauge is 15.0mm i.e. even further outside the NMRA spec than 00-SF.

 

Consequently, many modellers are used to the idea that models bump through crossings, drop into crossing gaps, collide with the nose of the vee, etc., and accept this as normal operation. For some this has been happening all their modelling life.

 

So the improved running of their RTR models on 00-SF is very noticeable, even if it is less than perfect on some wheels which exceed the BEF. In most cases the interference is not so great that it can't be mitigated with some careful rounding of the vee nose, and much less than it would be with the same wheels on Peco track.

 

Peco's 15.0mm check gauge originates from the much coarser wheels used on UK RTR models 20+ years ago when they were made in the UK (now all made in the Far East). Presumably Peco continue with it for compatibility with those older models, and because of the high cost of re-tooling.

 

There are at least 4 track standards using the 15.2mm min check gauge, so 00-SF is hardly alone in infringing the NMRA standard in that regard:

 

00-SF

00-BF

DOGA-Intermediate (15.2mm BEF max, check gauge 15.25mm min)

H0-SF (Terry Flynn's AMRA standards)

 

regards,

 

Martin.

Edited September 2, 2015 by martin_wynne

[47137]

Consequently, many modellers are used to the idea that models bump through crossings, drop into crossing gaps, collide with the nose of the vee, etc., and accept this as normal operation. For some this has been happening all their modelling life.

Martin,

This is one of the most poignant quotes I have ever read on these forums. It makes me smile too; but above all it seems most usefully substantive.

Thank you.

- Richard.

[dasatcopthorne]

Hi,

 

Not so. The original purpose of 00-SF (then called "EM minus 2") was to demonstrate the improved running of BRMSB 00 wheels on 1.0mm flangeways (as used in EM) instead of the usual 1.25mm flangeways used for BRMSB 00.

 

That was in the early 1970s. I don't recall anything equivalent to DOGA-Fine being in use at that time, otherwise there would have been no need for "EM minus 2". At that time there was no thought of any relevance to RTR models, which were children's toys in those days.

 

I have written more about the history of 00-SF here: http://www.rmweb.co.uk/community/index.php?/topic/94567-00-sf-and-00-bf-can-you-mix/page-10&do=findComment&comment=1992551

 

Full information about 00-SF is on its own page here: http://00-sf.org.uk

 

regards,

 

Martin.

Wow. Martin, I proud of you.

 

You've resisted setting it all out again.

 

Keep it up mate.  :)

 

Dave.

 

Oh. And I thought you said you were buggering off!